The present invention relates generally to thermoplastic webs of film. More specifically, the present invention relates to a film structure for creating two webs of film each preferably having a sterile surface.
It is known to utilize thermoplastic webs of film to create flexible containers for housing products. These flexible containers can be utilized in many industries and are utilized in the medical industry for containing, inter alia, parenteral solutions such as intravenous solutions, dialysis solutions, frozen drugs, nutrition products, respiratory therapy products, and plasma. When these containers are utilized in the medical industry, because they will contain fluids or solids that are introduced into a patient's body, it is necessary for the containers to be: essentially transparent; flexible; essentially free of extractables; and capable of maintaining the product contained therein under sterile conditions until the product is accessed or removed from the flexible containers.
There are a variety of methods through which a web of film can be created into a flexible container for housing a product, such as a medical product. One such method is to take two identical webs of film and seal them along their edges to create a container for housing a product. Another method is to create, in, for example, a form, fill, seal packaging machine, a flexible container for housing a product.
In either of these methods, it is necessary, if the web of film to be used to provide a sterile or clean containment area, for the film to be washed and/or sterilized typically before it enters the packaging machine, but, at least before it is created into a flexible container. One method for so washing the film is to utilize a bath through which the film is passed. The bath houses a solution such as, for example, a solution of hydrogen peroxide, that functions to wash the film before the film is fed into the packaging machine.
It would be desirable, if the web of film could be supplied to the packaging machine in a sterile state so that a washing and/or sterilizing step would not be required. This is especially true in aseptic or sterile packaging machines wherein the product is created in a sterile manner so that the resultant flexible container housing the product does not have to be terminally sterilized.
As set forth above, the web of film that is to be utilized to create a flexible container for housing medical products must meet certain criteria and demands. Among these demands is the ability to create sufficiently strong heat seals so t hat the web of film can be sealed onto itself, or onto an identical web of film, to create a container. In the medical industry, again, the strength of such heat seals is critical. For flexible containers that house parenteral products, the resultant containers, typically, must survive a six foot drop test.
Furthermore, the webs of film should have constructions that allow them to be processed on conventional machinery to create flexible containers; otherwise, the packaging machinery would have to be modified. In this regard, the web of film should be constructed so that it can be processed on conventional machinery and can be sealed utilizing conventional machinery, or conventional machinery that is slightly modified, and still provide sufficiently strong seals.